60 lines
1.4 KiB
Java
60 lines
1.4 KiB
Java
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Background tasks
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package com.ack.web.servlet;
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import java.io.IOException;
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import javax.servlet.ServletException;
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import javax.servlet.http.HttpServlet;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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public class BackgroundTasks extends HttpServlet {
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private Ticker ticker;
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public void init() {
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ticker = new Ticker();
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Thread t = new Thread( ticker );
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t.start();
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}
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public void doGet( HttpServletRequest req, HttpServletResponse res )
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throws ServletException, IOException {
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// this servlet processes requests and has a background
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// thread running to handle the execute of ticker objects
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// do not pass HttpServletRequest and HttpServletResponse to
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// background threads
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res.setContentType( "text/html" );
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res.getWriter().println( "check your console, i'm ticking<br>" );
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}
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public void destroy() {
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ticker.stop();
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}
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}
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// background task
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class Ticker implements Runnable {
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private volatile boolean keepAlive = true;
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private int count;
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public synchronized void stop() {
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keepAlive = false;
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}
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public void run() {
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while( keepAlive ) {
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System.out.println( "still alive [" + ( count++ ) + "]" );
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try {
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Thread.currentThread().sleep( 5000 );
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}
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catch( InterruptedException ie ) {
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ie.printStackTrace();
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}
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}
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}
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}
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